Transcript Chapter 1 Unit C

Chapter 1 Unit C
Changes to Earth’s Surface
Lesson 1 Changes to Earth’s Surface
 Landforms: - physical
features on Earth’s
surface.
 Glaciers
 Mountains
 Valleys
 Beaches
 Canyons
 Plains
 What forms these
different landforms?
 Water
 Wind
 Ice
 Mass Movement
Water
 Weathering – is the
process of breaking rock
into silt, clay, sand or
other tiny pieces called
sediment.
 Erosion – the process of
moving sediment from
one place to another.
 Deposition – the process
of dropping or depositing
sediment in a new
location.
 Water can carve
canyons, waves can
erode beaches and cliffs.
Water can break rocks
into smaller pieces and
move them to a new
place. This can be done
through rivers, oceans,
streams, etc.
Wind
 Wind can move sediment
from one place to
another. It can erode a
lot of sediment.
 Wind erosion can create
arches, columns, dunes,
and rocks that look like
tables
Ice
 Glaciers- are thick sheets
of ice, formed in areas
where more snow falls
during the winter than
melts during the
summers.
 There are two kinds of
glaciers:
1. Valley Glaciers – are
found high in mountain
valleys, creating U –
shaped valleys
2. Continental glaciers –
are ice sheets that
cover larger areas of
the Earth’s surface.

Ex: Greenland &
Antarctica
Mass Movement
 Mass Movement- is the
downhill movement of
rock and soil because of
gravity.
 Mudslides and landslides
occur quickly and
change landforms
suddenly.
 Creep is when soil
moves slowly down hill
over time due to gravity.
 Sinkholes are a large
hole in the ground that
appears suddenly, after
the ground underneath
it has become weak.
 http://www.evtv1.com/pl
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Review Questions
1. What is erosion?
2. What is deposition?
3. What forces cause erosion and deposition?
4. Why is weathering so important to life on land?
5. A type of mass movement is?
a) Glacier
b) Delta
c) Mudslide
d) Terminal moraine
Chapter 1 Lesson 2
Mountains, Volcanoes & Earthquakes
Earth’s Interior
 Earth has three distinct layers.
 Crust – is the outer later and it
is made of rock.
 Mantle – is the layer of rock just
below the crust.
 It is soft like melted candy.
 Core – is the center of the Earth.
 It is very hot and contains 2
parts:
 Outer core – molten rock
 Inner core – solid iron
We’re Moving?
 Earth’s surface is always
moving.
 Plates – are rigid blocks
of crust and upper
mantle rock.
 There are twelve major
plates that fit together
like puzzle pieces.
 They float on the soft
rock of the mantle.
Mountains
 Mountains form when Earth’s
crust folds, cracks, and bends
upward because of plate
movement.
 The highest mountains form
where plates collide.
 Ex: Himalayas
 Mountain don’t just form at
plate boundaries. They can
form wherever pressure is
great enough to push rock
upward.
 Mountains form in the ocean
too!
 Where plate pull apart
Magma builds up and form
underwater mountain
chains.
Mid-Atlantic Ridge
Volcanoes
 Volcano – is a mountain
formed by lava and ash.
 Magma – is molten rock
from Earth’s mantle.
 Lava – is magma that
reaches Earth’s surface.
 Ash – is small pieces of
hardened lava.
Volcanoes continued….
Three Types of Volcanoes
 Shield Volcano – are
broad with gentle
slopes. They are mostly
lava.
 Cinder Cone Volcano –
are tall and narrow with
steep slopes. They are
mostly ash.
 Composite Volcano – are
wide and have fairly
steep slopes. They are
lava & ash.
Mauna Loa is the largest
volcano in the world; it is a
shield volcano
Volcanoes continued…
Cinder Cone Volcano
Ring of Fire
Earthquakes
 An earthquake – is a
shaking of the ground
caused by the sudden
release of energy in
Earth’s crust.
 It occurs due to a
sudden release of energy
in Earth’s crust.
 The energy comes from;
plates crushing together,
scraping past each other
or bending along jagged
boundaries.
 Faults – breaks in Earth’s
plates where pieces of
crust move.
How are Earthquakes measured?
•
Earthquakes send
out energy in the
form of seismic
waves. The
intensity of these
waves are measured
using a seismic
graph.
•
Strength of
earthquakes is
measured on a
Richter scale from 010.
•
The worst recorded
Earthquake was in
Chile May 22, 1960
with a magnitude of
9.5
Review Questions
1. Describe three ways in which Earth’s plates interact.
2. What is magma and where does it comes from?
3. How do volcanoes form where oceanic and continental
plates collide?
4. Assume that the overall size of Earth’s crust stays the same.
If one plate is pushing away from the plate next to it on one
side, what must be happening at the boundary with another
plate on the opposite side?
5. Many strong earthquakes are caused by?
a) Plates sliding past each other
b) Lava flowing down the side of a volcano
c) Plates spreading apart
d) Hot magma
Chapter 1 Lesson 3
How Earth’s Surface Has Changed
Continental Drift
 Continental drift- is the
theory of how Earth’s
continents move over it’s
surface.
 225 million years ago
Earth was one
supercontinent called
Pangea.
What do you predict Earth will
look like 200 million years from
now?
 The Atlantic Ocean is
getting wider pulling
North America and
Europe farther apart.
 The Pacific Ocean is
getting smaller.
 Australia is moving
North.
Fossils
 Fossils – are the remains
or traces of past life
found in some rocks.
 Scientists study fossil to
find out how life has
changed on Earth.
 Most fossils are not the
actual remains of the
organisms but traces left
behind after they have
dissolved or decayed.
Review Questions
1. What was Pangea?
2. How old are the oldest rocks of the Grand Canyon?
3. How do we know that Earth’s life was different in the
past?
4. Why is the Grand Canyon important to scientists
studying Earth’s past?
5. The Southern continent that existed 200 million years
ago was called?
a) Gondawana
b) Precambria
c) Laurasia
d) Eurasia